diff --git a/.github/workflows/dod.yml b/.github/workflows/dod.yml
index bf01dce..6df2d1f 100644
--- a/.github/workflows/dod.yml
+++ b/.github/workflows/dod.yml
@@ -86,7 +86,7 @@ jobs:
           PR_TITLE: ${{ github.event.pull_request.title }}
         run: |
           set -euo pipefail
-          echo "$PR_TITLE" | npx --yes commitlint --extends @commitlint/config-conventional || {
+          echo "$PR_TITLE" | npx --yes -p @commitlint/cli -p @commitlint/config-conventional commitlint --extends @commitlint/config-conventional || {
             echo "::error::Título do PR não segue Conventional Commits (ex: feat: ..., fix: ..., chore: ...)."
             exit 1
           }
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9dac081..ecc782b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,11 +7,17 @@ Format follows [Keep a Changelog 1.1.0](https://keepachangelog.com/en/1.1.0/) an
 ## [Unreleased]
 
 ### Added
-- Standalone Python distribution `simplicio-mapper` on PyPI: dependency-free
+- Standalone Python distribution `simplicio-mapper` on PyPI: lightweight
   `simplicio_mapper.mapper` port of the Node mapper plus a `map` / `update` CLI
   exposed as the `simplicio-mapper` and `llm-project-mapper` console scripts.
   Generates the same `.simplicio/project-map.json` and `precedent-index.json`
   without requiring a Node toolchain.
+- Performance optimizations for the Python mapper (closes #82): `orjson` for
+  faster JSON serialization, persistent `diskcache` of per-file processing keyed
+  by path/size/mtime, and `__slots__`-backed internal models (`ProjectFile`,
+  `CodeEntity`, `PrecedentItem`) for lower memory on large projects. Schema and
+  artifact contracts remain stable; the package now ships with two lightweight
+  runtime dependencies (`orjson`, `diskcache`) instead of being dependency-free.
 - `map` / `update` CLI subcommands for generating and incrementally refreshing
   `.simplicio/project-map.json` and `.simplicio/precedent-index.json`.
 - Rich machine-readable mapper artifacts with file inventory, roles, imports,
diff --git a/README.md b/README.md
index f3bc326..7a754e7 100644
--- a/README.md
+++ b/README.md
@@ -50,8 +50,10 @@ npx @wesleysimplicio/llm-project-mapper update
 
 ### New: standalone Python CLI
 
-The mapper now ships as a dependency-free Python package, so Python-first teams
-can generate the same artifacts without a Node toolchain:
+The mapper now ships as a Python package with lightweight performance
+dependencies (`orjson` for JSON serialization and `diskcache` for a persistent
+file-processing cache), so Python-first teams can generate the same artifacts
+without a Node toolchain:
 
 ```bash
 pip install simplicio-mapper
diff --git a/README.pt-BR.md b/README.pt-BR.md
index 9213261..bbd55b2 100644
--- a/README.pt-BR.md
+++ b/README.pt-BR.md
@@ -49,8 +49,10 @@ npx @wesleysimplicio/llm-project-mapper update
 
 ### Novidade: CLI Python standalone
 
-O mapper agora tambem e distribuido como pacote Python sem dependencias, para
-times Python-first gerarem os mesmos artefatos sem toolchain Node:
+O mapper agora tambem e distribuido como pacote Python com dependencias leves
+de performance (`orjson` para serializacao JSON e `diskcache` para cache
+persistente de processamento de arquivos), permitindo times Python-first gerar
+os mesmos artefatos sem toolchain Node:
 
 ```bash
 pip install simplicio-mapper